2,5,6-trimethylcyclohex-2-en-1-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 1 liter round-bottomed flask, at room temperature, were successively added CH2Cl2 (400 ml), BHT (100 mg) and a 1 M solution of EtAlCl2 in hexanes (80 ml; 0.08 mol). 2,5,6-trimethylcyclohex-2-en-1-one (55.2 g, 0.4 mol, 3:2 mixture of two isomers) was added dropwise, while maintaining the internal temperature below 30° C. Then butadiene (43.2 g, 0.8 mol) was added in one portion. The reaction was stirred at room temperature for 15 days. The reaction was then poured onto cold 5% aqueous HCl and extracted twice with ether. The organic layers were washed with saturated aqueous NaHCO3, water and brine and dried over solid sodium sulfate. The crude product was distilled to give 50 g of a liquid which was then chromatographed on silicagel (heptane:ethyl acetate 49:1) then purified by bulb-to-bulb distillation (B.P.=90° C./0.021 mbar) to give the totle compound (39.43 g, 0.205 mol, 51%) as a 3:2 mixture of diastereoisomers. In a 1 liter round-bottomed flask, at room temperature, were successively added while maintaining the internal temperature below 30° C extracted twice with ether The organic layers were washed with saturated aqueous NaHCO3, water and brine dried over solid sodium sulfate The crude product was distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 1 liter round-bottomed flask, at room temperature, were successively added CH2Cl2 (400 ml), BHT (100 mg) and a 1 M solution of EtAlCl2 in hexanes (80 ml; 0.08 mol). 2,5,6-trimethylcyclohex-2-en-1-one (55.2 g, 0.4 mol, 3:2 mixture of two isomers) was added dropwise, while maintaining the internal temperature below 30° C. Then butadiene (43.2 g, 0.8 mol) was added in one portion. The reaction was stirred at room temperature for 15 days. The reaction was then poured onto cold 5% aqueous HCl and extracted twice with ether. The organic layers were washed with saturated aqueous NaHCO3, water and brine and dried over solid sodium sulfate. The crude product was distilled to give 50 g of a liquid which was then chromatographed on silicagel (heptane:ethyl acetate 49:1) then purified by bulb-to-bulb distillation (B.P.=90° C./0.021 mbar) to give the totle compound (39.43 g, 0.205 mol, 51%) as a 3:2 mixture of diastereoisomers. In a 1 liter round-bottomed flask, at room temperature, were successively added while maintaining the internal temperature below 30° C extracted twice with ether The organic layers were washed with saturated aqueous NaHCO3, water and brine dried over solid sodium sulfate The crude product was distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a stirred autoclave having a useful capacity of 300 parts by volume, a solution of 35 parts of 2,3,6-trimethylcyclohex-5-en-1-one in 35 parts of N-methylmorpholine, 34 parts of ammonia and 5 parts of a finely divided catalyst, containing 0.5% by weight of Pd and 0.1% by weight of Zn on Al2O3, are kept for 10 hours at 230° C. and the autogenous pressure (about 150 bar). The mixture is then allowed to cool, filtered and purified by distillation. 18.2 parts of 2,3,6-trimethylaniline and 15.3 parts of 2,3,6-trimethylcyclohexan-1-one are obtained, the latter presumably through partial hydrogenation of the 2,3,6-trimethylcyclohex-5-en-1-one starting material with the hydrogen formed during the reaction. Since 2,3,6-trimethylcyclohexan-1-one can in turn be converted to the desired 2,3,6-trimethylaniline, for example as described in Example 1 or 2, the selectivity of the reaction is 96%. to cool filtered purified by distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,000 parts by volume of catalyst are introduced into a fluidised bed reactor, having a capacity of 1.3 liters or 1,300 parts by volume. The catalyst consists of 0.5% by weight of Pd, 0.11% by weight of Zn and 0.1% by weight of Cd on Al2O3 and has a particle size of from 0.2 to 0.6 mm. The reactor is set to 230° C. and, per hour, a correspondingly preheated mixture of 200,000 parts by volume of ammonia and 10,000 parts by volume of hydrogen is passed in. Per hour, a solution of 50 parts of 2,3,6-trimethylcyclohex-5-en-1-one in 50 parts of N-methylpiperidine is sprayed continuously into the fluidised catalyst bed produced by the gas stream. The reaction product is isolated by cooling the exit gases, and is distilled. 100 parts of 2,3,6-trimethyl-cyclohex-5-en-1-one give 89 parts of 2,3,6-trimethylaniline; yield: 91%. 1,000 parts by volume of catalyst are introduced into a fluidised bed reactor The reactor is set to 230° C. and, per hour produced by the gas stream The reaction product is isolated by cooling the exit gases is distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1000 g of 2,5,6-trimethyl-2-cyclohexen-1-one is passed per hour per liter of catalyst at atmospheric pressure through an externally heated tube having a capacity of 250 cm3 and filled with a palladium/silica gel catalyst (0.2% by weight of palladium), the temperature being 300° C. The yield is 96% of 2,3,6-trimethylphenol. 4% of starting material is recovered and returned to the reaction. being 300° C

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 102 g of β-methoxybutyraldehyde is dripped in the course of one hour into a mixture of 500 g of diethyl ketone and 10 g of a 30% solution of sodium methylate in methanol which is boiling under reflux. The whole is then heated for another hour under reflux. The reaction mixture is processed as described in Example 2. 77 g of 2,5,6-trimethyl-2-cyclohexen-1-one is obtained, i.e. a 56% yield with reference to β-methoxybutyraldehyde. under reflux The whole is then heated for another hour under reflux

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 88 g of β-hydroxybutyraldehyde and 150 g of diethyl ketone is added dropwise in the course of one hour to a mixture of 250 g of diethyl ketone, 80 g of isopropanol and 5 g of sodium hydroxide powder which is boiling under reflux. The whole is boiled for another hour under reflux. Neutralization is effected with glacial acetic acid and the aqueous phase is separated. The organic layer is fractionated. 65 g of 2,5,6-trimethyl-2-cyclohexen-1-one having a boiling point of 74° to 76° C. at 12 mm Hg is obtained. The yield is 47% with reference to β-hydroxybutyraldehyde. under reflux The whole is boiled for another hour under reflux the aqueous phase is separated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 70 g of crotonaldehyde is dripped in the course of one hour into a mixture of 400 g of diethyl ketone and 10 g of a 30% solution of sodium methylate in methanol which is boiling under reflux and the reaction mixture is boiled for another half hour under reflux. The whole is neutralized with glacial acetic acid and the mixture obtained is filtered. 325 g of diethyl ketone is recovered by distillation of the filtrate; 55 g of 2,5,6-trimethyl-2-cyclohexen-1-one having a boiling point of from 74° to 76° C. at 12 mm Hg is obtained. The yield with reference to crotonaldehyde is 40%. under reflux under reflux the mixture obtained is filtered 325 g of diethyl ketone is recovered by distillation of the filtrate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Dehydrogenation may be carried out in an inert solvent. It is advantageous however to dehydrogenate the 2,5,6-trimethyl-2-cyclohexen-1-one or 2,3,6-trimethyl-2-cyclohexen-1-one in the gas phase, for example by passing it as a gas at the dehydrogenation temperature over a palladium/silica gel catalyst. In gas-phase dehydrogenation the trimethyl-2-cyclohexen-1-one is preferably passed over the catalyst in admixture with an extraneous gas such as nitrogen, steam, carbon dioxide and particularly hydrogen; generally a ratio by volume of extraneous gas to gaseous trimethyl-2-cyclohexen-1-one of from about 1:2 to 5:1 is chosen. Temperatures of from 200° to 400° C., preferably from 250° to 350° C., are usually used in gas-phase dehydrogenation. The time that the trimethyl-2-cyclohexen-1-one is in contact with the catalyst is generally from half to fifty, preferably from two to ten seconds. The 2,3,6-trimethylphenol is obtained in a more than 95% yield in gas-phase dehydrogenation. of from 200° to 400° C. preferably from 250° to 350° C. is generally from half to fifty, preferably from two to ten seconds

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a stirred autoclave having a useful capacity of 300 parts by volume, a solution of 35 parts of 2,3,6-trimethylcyclohex-5-en-1-one in 35 parts of N-methylmorpholine, 34 parts of ammonia and 5 parts of a finely divided catalyst, containing 0.5% by weight of Pd and 0.1% by weight of Zn on Al2O3, are kept for 10 hours at 230° C. and the autogenous pressure (about 150 bar). The mixture is then allowed to cool, filtered and purified by distillation. 18.2 parts of 2,3,6-trimethylaniline and 15.3 parts of 2,3,6-trimethylcyclohexan-1-one are obtained, the latter presumably through partial hydrogenation of the 2,3,6-trimethylcyclohex-5-en-1-one starting material with the hydrogen formed during the reaction. Since 2,3,6-trimethylcyclohexan-1-one can in turn be converted to the desired 2,3,6-trimethylaniline, for example as described in Example 1 or 2, the selectivity of the reaction is 96%. to cool filtered purified by distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,000 parts by volume of catalyst are introduced into a fluidised bed reactor, having a capacity of 1.3 liters or 1,300 parts by volume. The catalyst consists of 0.5% by weight of Pd, 0.11% by weight of Zn and 0.1% by weight of Cd on Al2O3 and has a particle size of from 0.2 to 0.6 mm. The reactor is set to 230° C. and, per hour, a correspondingly preheated mixture of 200,000 parts by volume of ammonia and 10,000 parts by volume of hydrogen is passed in. Per hour, a solution of 50 parts of 2,3,6-trimethylcyclohex-5-en-1-one in 50 parts of N-methylpiperidine is sprayed continuously into the fluidised catalyst bed produced by the gas stream. The reaction product is isolated by cooling the exit gases, and is distilled. 100 parts of 2,3,6-trimethyl-cyclohex-5-en-1-one give 89 parts of 2,3,6-trimethylaniline; yield: 91%. 1,000 parts by volume of catalyst are introduced into a fluidised bed reactor The reactor is set to 230° C. and, per hour produced by the gas stream The reaction product is isolated by cooling the exit gases is distilled

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1000 g of 2,5,6-trimethyl-2-cyclohexen-1-one is passed per hour per liter of catalyst at atmospheric pressure through an externally heated tube having a capacity of 250 cm3 and filled with a palladium/silica gel catalyst (0.2% by weight of palladium), the temperature being 300° C. The yield is 96% of 2,3,6-trimethylphenol. 4% of starting material is recovered and returned to the reaction. being 300° C